The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 03, 2013
Filed:
Mar. 11, 2008
Prasad S Gudem, San Diego, CA (US);
Li-chung Chang, Irvine, CA (US);
Prasad S Gudem, San Diego, CA (US);
Li-Chung Chang, Irvine, CA (US);
QUALCOMM, Incorporated, San Diego, CA (US);
Abstract
Techniques for performing transmit (TX) leakage cancellation are described. A receiver includes a low noise amplifier (LNA) and a TX leakage canceller. The LNA amplifies a receiver input signal and provides an amplified signal. The TX leakage canceller includes a downconverter, a notch filter, and an upconverter. The downconverter downconverts a canceller input signal (e.g., obtained from the LNA output) with a first LO signal at a transmit frequency and provides a downconverted signal. The notch filter filters the downconverted signal to pass an undesired signal (e.g., a TX leakage signal) and attenuate a jammer and a desired signal in the canceller input signal. The upconverter upconverts the filtered signal with a second LO signal at the transmit frequency and provides a feedback signal. The feedback signal is subtracted at the input or output of the LNA to cancel the undesired signal.